12 Common Chemicals Used in Medicine – Types and Examples

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In a pharmaceutical preparation, in addition to the active ingredient drug products also required excipients / additives. The excipient is an ingredient other than the active substance added in the formulation of a drug preparation for various purposes or functions. Although excipients are not the active substances, excipients are essential in pharmaceutical production to enhance the acceptability of patient.

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IPEC (The International Pharmaceutical Excipients Council) divides the excipients for solid preparations in several general categories based on their functions, there are: binders, disintegrant, fillers, lubricants, glidant, dyes, sweeteners, preservatives, suspending agents / dispersants, antioxidant, and coating material.

Excipients or additives in drug are defined as additives used to convert the active ingredient into the appropriate pharmaceutical preparation form for use in the patient. The International Pharmaceutical Excipients Council (IPEC) defines Pharmaceutical excipients as non-drug or pro-drug substances that have been evaluated for safety and are intended for drug delivery systems for the following purposes:

To assist during the manufacturing process

Protect, support and improve stability and bioavailability of drug

To assist in product identification

Improve product safety and effectiveness during drug distribution and usage

Some of the most common general criteria for excipients are it must be physiologically neutral, physically and chemically stable, comply with legislation, do not affect the bioavailability of the drug, are free of pathogenic microbes and are available in sufficient quantities and are inexpensive.

Some experts also stated that excipients are the pharmacologically inert substances that are used as additives in drug formulations especially in tablet form to improve the properties of active substances, forming tablets and facilitating tablet-making technology.

At this time we will discuss excipients within the pharmaceutical form of tablets in particular. Excipients have a very important role or function in tablet formulation. This is because there is no single active substance that can be directly compressed into a tablet without the need for excipients. Therefore, we would like to explain more about the additional ingredients that can be encountered in the manufacture of drugs below.

1. Binders

Binders serve to provide adhesion to the mass of powders in granulation and direct compression of tablet and to increase the cohesion that is already present in the filler agent. The binder may be added in the dry form and the solution form (more effectively). The binder in general can be distinguished into: natural binders, synthetic / semisynthetic polymers and sugars.

In wet granulation, the binder is usually added in solution form (made solution, muchilago or suspension), but can also be added in dry form, after mixing with the mass to be granulated with added solvent.

Binders that is usually used is mucilago Gummi Arabici 10 -20% (hot solution of Methyl cellulose 5%). The other binders that may be found in tablet are:

2. Disintegrant

The bioavailability of a tablet depends on the absorption of the drug. Drug absorption depends on drug solubility in gastrointestinal fluid and drug permeability across the membrane. The solubility rate of a drug in a tablet depends on the physico-chemical properties of the drug, as well as the speed of disintegration and dissolution of the tablet. To accelerate the disintegration of tablets, then added disintegrant. The disintegrant will assist the destruction of the tablet into granules, furthermore particles of the constituent particles thereby increasing the speed of tablet dissolution.

3. Filler

Filler in drug formulation serves to enlarge the mass volume of drug to make it easy to be compressed or produced. Fillers are added if the active ingredients are slightly harder to be compressed. The usually used filler in drug preparation are Saccharum lactis, Amylum manihot, calcium phospas, calcii carbonas and other suitable substances.

There are fillers that can be used also as the binder, and they are called filler-binders. Filler-binders is a filler that also has the ability to increase the flow power and compactability of tablet mass. Filler binders are used in direct compression. The requirement of a material to have a function as a filler-binders is to have good fluidity and compactibility. The material having such properties usually has a relatively large particle size (not in fines form) with a spherical shape. Fillers that can have a function as filler-binders are usually modified, including co-processed diluents. Co-processed diluents are modified materials and combinations of 2 or more materials with appropriate processes.

4. Lubricant

Lubrikan is a material that serves to reduce friction between the surface of the tablet’s wall / edge with the die wall during compression and ejection as well as prevent the mass of tablets attached to the mold. The lubricant is added to the final mixing / mixing, prior to the compression process.

Lubricants can be classified according to their solubility in water which are water soluble and insoluble in water. The lubricant selection consideration depends on the usage, type of tablet, the prefered disintegration and dissolution properties, physico-chemical properties of powder / granule and cost.

5. Glidant

Glidant is the ingredients that improve the flowing ability of powders, and are generally used in direct compression without granulation process.

Glidants are added in the formulation to increase the mass fluidity to be compressed, so that the mass can fill the die in uniform quantities. Amylum is the most popular glidant because it can also function as glidan as well as disintegrant with concentration up to 10%. Talc is better as a glidant than starch, but it can decrease the disintegration and dissolution of tablets.

6. Dyes and pigment

Dyes and pigment in pharmaceutical industry serves to mask unfavorable medicinal colors, product identification, and to make a product more appealing.

The dye does not have therapeutic activity, and can not increase the bioavailability or stability of the product, but the dye is added to the tablets preparation for the function of masking the drug color, the identification of the product, and to make the product more attractive (aesthetic appearance and brand image in the market ). However, inappropriate or incorrect dyeing will affect the quality of the product. The dye used should be the dye permitted by law to be used as a dye for the preparation of the drug.

The dyestuffs are water-soluble and there is also dyes that are insoluble in water. Dyes are added in the form of a solution or suspension in wet granulation, depending on whether the dye is soluble or not. The use of soluble dyes may result in dye migration during the drying process which may lead to uneven color. The use of insoluble dyes can reduce the risk of possible interactions with active substances and other additives. For the dyeed tablets, it is important to measure the uniformity of the color of the shine, as well as the color change due to the influence of light on the tablet surface.

7. Sweetener

The addition of sweeteners and flavors is usually only for chewable, suction, buccal, sublingual, effervescent and other tablets that are intended to break down or dissolve in the mouth.

Sweeteners that may be added in drug formulation are whether the natural sweetener or synthetic sweetener. The examples of natural sweeteners are mannitol, lactose, sucrose, and dextrose. Meanwhile the synthetic sweeteners that may be added in pharmaceutical industry are saccarine, cyclamate, and aspartame.

Saccharin is 500 times sweeter than sucrose, its flavor is bitter at the end and is carcinogenic, just as cyclamate is also carcinogenic. Aspartame is 180 times sweeter than sucrose, but is less stable in humid conditions so it can not be used with hygroscopic components.

8. Preservatives

Preservatives are natural or synthetic chemicals that are added to various products in order to help prevent the microbial decomposition. Preservation is a process of preventing or inhibiting the microbial growth. In the pharmaceutical industry, preservation is usually done by adding preservatives to a drug product, with the main purpose for minimizing microbial growth (such as in oral, topical, etc. preparation), or can also reduce microbial growth (such as sterile preparations like injection preparations).

Some of the factors that are involved in selecting preservatives are to pay attention to the concentration, pH, taste, odor and solubility of preservatives. In some products, such as syrup, the product is inherently preserved with a high concentration of sugar present in it wherein sugar also acts as an osmotic preservative.

However, in most preparations, appropriate preservatives should be selected and actually considered for assuring the chemical or physical stability of drug product. The preservative characteristics used should not be toxic, stable, compatible and inexpensive and have acceptable taste, odor and color. In addition, preservatives should also be effective against various bacteria, fungi and yeast.

9. Antioxidant

Antioxidants are one of the additional ingredients commonly added to pharmaceutical preparations to improve the physical and chemical stability of drug products. Antioxidants are added to minimize the oxidative processes that occur in some drugs or excipients that are exposed to oxygen or in the presence of free radicals. This oxidation process occurs because it is catalyzed by light, temperature, hydrogen ion concentration, the presence of trace metal, or peroxide substance.

Some compounds are susceptible to oxidation such as unsaturated oils / fats, with aldehyde or phenolic groups, colors, flavors, sweeteners, plastics and rubber, which will be used in containers for the final product.

Oxidation can manifest in the change of taste, appearance, precipitation, unpleasant color changes, or even a slight loss of potency. There is a rancid term cited on many of the distinctive aromas produced from the automatic oxidation of unsaturated fatty acids present in oils and fats, and it affects numerous other oils and fats. The distinct rancid odor can occur due to short chain and volatile monomers resulting from the longer chain divisions, less stable oils and fats.

10. Suspending agent

Suspending agent functions in pharmaceutical product is to disperse insoluble particles into the carrier and increase the viscosity of product so that the settling speed can be minimized. The mechanism of action of the suspending agent is to increase viscosity, but excessive viscosity will complicate reconstitution by shaking.

Suspending agents are divided into several classes: cellulose drivat, polysaccharide, clay. However, not all suspending agents are suitable for use and sometimes it needs to bee given in combination.

Examples of suspending agents are:

Suspending agent that includes in group of goms. The examples are: Acasia (Pulvis gummi arabici), Chondrus, Tragacanth, Algin

Suspending agent that does not include in group of goms. The examples are: Bentonite, Hectorit and Veegum.

11. Coating Agent

The coating agent in pharmaceutical products especially in tablet has several functions as follows:

Covering the unpleasant taste and odor of the active substances and allowing the patient to swallow it easily

Protects the active substances against external influences, such as moisture, oxygen, light, etc.

Controlling drug release (active substances) from tablets

Protect the drug substancces from the extreme environement in the stomach, increase the attractiveness (aesthetics) of drug products and facilitate the identification of dosage form

Prevent the incompatibilities among active substances and exipients that are contained in tablets

Combine the other drugs or help the formulation in tablet coating (for example if the tablet is too small and too large)

The examples of coating agents that can be found in the drug are: HPMC, MHC, ethyl cellulose, HPC, povidone, Na-CMC, PEG, active polymers, cellulose derivate.

12. Flavoring Agent

Chemicals in Medicine, Flavoring agents are used to flavor or enhance flavors on tablets that are desired to dissolve in order to be more acceptable to consumers. Flavors may be added in spray dried flavors or in the form of oils or solvents (water soluble) flavors. The solid form of flavoring agent is easier to be handled and generally more stable than the oil form of flavoring agent.

The oil form is usually added at the lubrication stage because the oil is sensitive to moisture and tend to evaporate when heated at drying. So most likely it is adsorbed into the excipient and added to the lubrication process. Maximum addition of oil that can added to the granule without affecting the tablet’s character or the slaughtering process is 0.5-0.75. Aqueous flavors are not widely used because they are not stable because in the storage.

The examples of flavoring agents that commonly used in pharmaceutical products are glycerin, glucose, citric acid, peppermint oil, saccharin, orange oil, and many more.

Indeed there are many List of Common Chemicals in Medicine that are used in pharmaceutical industry. They are very useful in the drug formulation and very safe to be consumed by human if it is under the required dosage.